In the United States, while some telephone calls are handled by one service provider, e.g., a local call completed between wired (as opposed to wireless) telephone stations, many calls, e.g., long-distance calls, require multiple service providers to cooperate for their completion. The initial carrier providing telephone service is typically a local service provider, illustratively a local exchange carder (LEC), such as New Jersey Bell. However, the term "local service providers", as used herein, also includes cellular (wireless), cable and any so-called "dial-tone "or "first contact service" provider. Such local service providers are also, typically, the network of last contact for a call, because they are connected to the called subscriber, where the call exits the public network.
The network connecting the network of first contact with the network of last contact is typically, but not necessarily, that of a long-distance--or so-called interexchange (IXC)--telephone carrier. In the United States, AT&T, MCI and Sprint are three such IXCs. For example, presently, for a long-distance telephone call between wired telephone subscribers, the local service providers serving the calling and called telephones are two different LECs which are interconnected by a long-distance, or interexchange, carder.
In some call scenarios, there are only two networks connected together, the network of first contact and the network of last contact. For example, for a local call from a mobile telephone to a wired telephone station, the network of first contact is a cellular service provider while the network of last contact is a LEC connecting the network of the cellular service provider to a called party at the wired telephone station, both networks being those of local service providers. Thus, it is possible for a telecommunications carrier to serve multiple roles.
Presently, caller-identification, where information identifying the telephone number of the calling station is transmitted to the called station, is provided only by the network of last contact to the called subscriber. The network of last contact is typically the network of the local exchange carrier (LEC) that is directly connected to the called station set. Therefore, caller identification is only available on an intra-LATA basis, i.e., within the area that can be served by a LEC without involving an interexchange carrier (IXC). It has been a goal of the art, however, to provide advanced telephone features such as caller identification, on an inter-LATA basis, thereby allowing such features to be extended to nationwide functionality.
Indeed, it is envisioned by those skilled in the art that nationwide advanced telephone features will be provisioned and administered by the LECs who will, if necessary, contract or obtain certain functions from the interexchange carriers (IXCs). For example, the LECs will contract with the IXCs for the latter to provide the LEC with the calling party number (CPN) for each call. At present, this information is not provided to the LECs at all. The LEC will then determine if the called party was a subscriber to inter-LATA caller-ID and, if so, cause signals representing the calling party's telephone number to be sent to the called station set. However, such a system is wasteful of capacity in the IXC-LEC interface, in that it causes the IXC to transmit the calling party information for each call, while the information is only delivered to the subset of customers who subscribe to inter-LATA caller-ID.